What about the idea of making the common medals and special medals for the regions? (2-3 medals in the region will be enough)
also with ribbon (you have to make a separate window for each soldier medals)
+ ribbons to protect the city (not just the part, and the murder at least one alien per mission and 2-3 of these missions)
also best to get a medal is very difficult to get
for example, to get medal of honore, need to clear mission with 5-7 aliens by using only 1 soldier(1 soldier in chopper)
Medals shouldn't give a strong bonus, because stats rise quite quickly, especially if you do not quickly cleaned mission